Thermoplastic resins are used extensively as the material of choice for designing complex injection molded articles due to their malleability when molten (after exposure to heat). However, prolonged or excessive exposure to these heat regimes often cause the polymer to become unstable, compromising their mechanical properties or shortening their useful life cycle. This effect becomes more exaggerated as the processing temperatures and/or pressures are increased to force these polymers into thin-walled or narrow cavities.
An example of this is a flame retarded (with an aryl phosphate) thermoplastic polyester, poly(cyclohexylene dimethylene) terephthalate (PCT). Normal processing for this resin can easily reach temperatures of 275.degree.-300.degree. C. However extended processing periods can cause the composite to become unstable and ultimately compromise its effectiveness in a given application.